Ultrasound-mediated spatiotemporally controlled delivery of miRNAs regulates apoptosis and maturation of hiPSC-CMs at the organelle level to enhance the therapeutic effect of myocardial infarction

Purpose Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) hold great potential for the treatment of heart failure following myocardial infarction (MI). However, their therapeutic efficacy is limited by cell apoptosis and immature cellular functions after transplantation. miRNAs inhibit apoptosis and promote maturation in hiPSC-CMs, but their short half-life and the dynamic apoptosis/maturation balance of transplanted hiPSC-CMs require precise spatiotemporal intervention. Unfortunately, the lack of safe, precise, and highly reproducible miRNA delivery strategies has restricted the widespread translational application of this approach. To address this issue, we aim to construct miRNA-loaded ultrasound molecular probes and achieve precise spatiotemporal delivery of miRNAs via ultrasound-mediated technology to enhance the therapeutic effect of transplanted hiPSC-CMs. Methods In this study, we constructed two types of miRNA-loaded ultrasound molecular probes (hGVs-Ad): one co-delivers miR-199a with miR-30e-5p to exert an anti-apoptotic effect, and the other carries miR-452 with let-7i to promote hiPSC-CMs maturation. Through ultrasound-mediated delivery, we achieved precise spatiotemporal control over miRNA release and intracellular accumulation. We isolated nanoscale gas vesicles (hGVs) from Halobacterium NRC-1 and conjugated them with miRNA-encoding adenoviruses (Ad) via electrostatic adsorption to fabricate ultrasound molecular probes (hGVs-Ad). In a rat model of MI, we observed the penetration of hGVs-Ad and hGVs into the infarcted myocardium. By utilizing ultrasound-targeted microbubble destruction (UTMD) technology, we ruptured hGVs-Ad accumulated in the infarcted area. We adopted sequential delivery of Ad (miR-199a/miR-30e-5p at weeks 1-2, miR-452/let-7i at weeks 3-4 post-transplantation) to treat transplanted hiPSC-CMs. Results The fabricated ultrasound molecular probes (hGVs-Ad) exhibited an average particle size of 638.7 ± 62.78 nm and a zeta potential of 6.41 ± 1.55 mV. In a rat model of MI, both hGVs-Ad and hGVs could penetrate the infarcted myocardium, enabling the diagnosis of MI via ultrasound imaging. The released miRNAs from ruptured hGVs-Ad acted on transplanted hiPSC-CMs to further enhance cell maturation and anti-apoptotic capacity. Sequential delivery of Ad (miR-199a/miR-30e-5p at weeks 1-2, miR-452/let-7i at weeks 3-4 post-transplantation) more effectively enhanced hiPSC-CMs maturation and anti-apoptotic capacity at the transplantation site. Conclusion This study successfully constructed an ultrasound molecular probe (hGVs-Ad) capable of targeted accumulation in the MI site. Through UTMD technology, intravenous injection of hGVs-Ad enabled the effective release of recombinant adenovirus particles at the infarcted site, promoting the maturation of transplanted hiPSC-CMs and enhancing their anti-apoptotic capacity. This approach provides a novel strategy for the treatment of myocardial infarction.